User guide

FT 3120 / FT 3150 Smart Transceiver Data Book 81
Timer/Counter Output Objects
Figure 3.44 Edgedivide Output Object
Frequency Output
A timer/counter may be configured to generate a continuous square wave of 50% duty cycle. Writing a new
frequency value to the device takes effect at the end of the current cycle. This object is useful for frequency synthesis
Symbol Description Min Typ Max
t
fout
Function call to start of timer — 96 µs —
t
fod
Function to output disable — 82.2 µs —
t
sod
Active sync edge to output toggle 550 ns — 750 ns
t
win
Sync input pulse width (10MHz) 200 ns — —
t
ret
Return from function — 13 µs —
OUTPUT
SYNC INPUT
TIME
t
sod
START OF
io_out()
INTERNAL
COUNT
BEGINS
END OF
io_out()
START OF
io_out()
OUTPUT
INACTIVE
t
fod
t
fout
t
win
t
ret
Timer/Counter 1
Timer/Counter 2
IO10
IO9
IO8
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7
mux
Output
Sync
Input
Optional Pull-Up ResistorsHigh Current Sink Drivers